Index: firmware/App/Services/Reservoirs.c
===================================================================
diff -u -rd33b56765d3eeb3853eb84697d05c8a91441e00f -re2a7289fade72dfc5426629eeb288395d894b3ec
--- firmware/App/Services/Reservoirs.c	(.../Reservoirs.c)	(revision d33b56765d3eeb3853eb84697d05c8a91441e00f)
+++ firmware/App/Services/Reservoirs.c	(.../Reservoirs.c)	(revision e2a7289fade72dfc5426629eeb288395d894b3ec)
@@ -94,6 +94,7 @@
 static U32 previousDialysateFlowMLP;                                                                     ///< Previous dialysate flow rate in mL/min.
 static F32 previousUFFlowMLP;                                                                            ///< Previous ultrafiltration flow rate in mL/min.
 static DG_MIXING_RATIOS_T ratios;                                                                        ///< Mixing ratios and fill prep time in milliseconds structure.
+static U32 prevTargetFillVolumeML;                                                                       ///< Previous target fill volume in milliliters.
 
 static const F32 RESERVOIR_DILUTION_RATIO = MAX_RESERVOIR_DILUTION / ( 1.0 - MAX_RESERVOIR_DILUTION );   ///< Reservoir dilution ratio.
 
@@ -125,7 +126,7 @@
  * volSpentMl, reservoirsPublicationCounter, dilutionLevelPct, dgOpMode, dgSubMode,
  * timeReservoirInUse, volSpentUFML, activeReservoir, recirculationLevelPct,
  * reservoirSwitchStartTimeMS, timeWaitToFillMS, targetFillFlowLPM, ratios
- * previousDialysateFlowRate
+ * previousDialysateFlowRate, prevTargetFillVolumeML
  * @return none
  *************************************************************************/
 void initReservoirs( void )
@@ -153,6 +154,7 @@
     ratios.acidMixingRatio      = 0.0F;
     ratios.bicarbMixingRatio    = 0.0F;
     ratios.timeFillPrepMS       = 0;
+    prevTargetFillVolumeML      = 0;
 }
 
 /*********************************************************************//**
@@ -196,7 +198,7 @@
         volSpentML += ( flowRateMLPerMS * msSinceLastVolumeCalc );
         timeReservoirInUse++;
         // Check the recirculation level
-        recirculationLevelPct = volSpentML / (F32)getTargetFillVolumeBasedOnDialysateFlowML();
+        recirculationLevelPct = volSpentML / (F32)prevTargetFillVolumeML;
     }
 
     // Update the reservoir start time
@@ -336,21 +338,21 @@
 static void calculateActiveReservoirCycleTime( void )
 {
     U32 dialysateFlowMLP     = getTreatmentParameterU32( TREATMENT_PARAM_DIALYSATE_FLOW );
-    F32 fillTimeMS           = ( (F32)getTargetFillVolumeBasedOnDialysateFlowML() / ( getTargetFillFlowRateLPM() * ML_PER_LITER ) ) * SEC_PER_MIN * MS_PER_SECOND;
+    F32 fillTimeMS           = ( (F32)prevTargetFillVolumeML / ( getTargetFillFlowRateLPM() * ML_PER_LITER ) ) * SEC_PER_MIN * MS_PER_SECOND;
     F32 targetUFFlowMLP      = getCurrentUFSetRate();
-    F32 timeDepletionMS      = ( (F32)getTargetFillVolumeBasedOnDialysateFlowML() / dialysateFlowMLP ) * SEC_PER_MIN * MS_PER_SECOND;
+    F32 timeDepletionMS      = ( (F32)prevTargetFillVolumeML / dialysateFlowMLP ) * SEC_PER_MIN * MS_PER_SECOND;
     F32 timeTotalCycleMS     = fillTimeMS + RESERVOIR_FRESH_SETTLE_TIME_MS + RESERVOIR_CYCLE_EXTRA_MARGIN_TIME_MS + ratios.timeFillPrepMS;
     F32 timeReservoirCycleMS = 0.0F;
     F32 timeUFDepletionMS    = NEARLY_INFINITY;
-    F32 volFreshML           = getTargetFillVolumeBasedOnDialysateFlowML() - volSpentML;
+    F32 volFreshML           = prevTargetFillVolumeML - volSpentML;
     F32 timeFreshRemainingMS = ( volFreshML / (F32)dialysateFlowMLP ) * SEC_PER_MIN * MS_PER_SECOND;
-    F32 volMaxUFML           = getTargetFillVolumeBasedOnDialysateFlowML() * MAX_RESERVOIR_DILUTION;
+    F32 volMaxUFML           = prevTargetFillVolumeML * MAX_RESERVOIR_DILUTION;
 
     // Check if target UF flow is not zero to consider it in the calculations too
     if ( targetUFFlowMLP > NEARLY_ZERO )
     {
         // If UF is not 0, the active reservoir cycle time is minimum of UF depletion and fill time
-        timeUFDepletionMS = ( ( (F32)getTargetFillVolumeBasedOnDialysateFlowML() * RESERVOIR_DILUTION_RATIO ) / targetUFFlowMLP ) * SEC_PER_MIN * MS_PER_SECOND;
+        timeUFDepletionMS = ( ( (F32)prevTargetFillVolumeML * RESERVOIR_DILUTION_RATIO ) / targetUFFlowMLP ) * SEC_PER_MIN * MS_PER_SECOND;
         // Calculate the ultra-filtration remaining volume
         // Using the ultra-filtration remaining volume and the ultra-filtration target flow rate calculate the time
         // The depletion time in milliseconds is the minimum time of the fresh remaining time and the depletion remaining time
@@ -529,15 +531,17 @@
     {
         if ( DG_GEN_IDLE_MODE_STATE_FLUSH_WATER == dgSubMode )
         {
-            cmdStartDGFill( getTargetFillVolumeBasedOnDialysateFlowML(), targetFillFlowRateLPM );
+            prevTargetFillVolumeML = getTargetFillVolumeBasedOnDialysateFlowML();
+            cmdStartDGFill( prevTargetFillVolumeML, targetFillFlowRateLPM );
         }
     }
     // If we have active dialysate temp alarms, we want to fill immediately.
     else if ( TRUE == isDialysateTempAlarmActive() )
     {
         if ( DG_GEN_IDLE_MODE_STATE_FLUSH_WATER == dgSubMode )
         {
-            cmdStartDGFill( getTargetFillVolumeBasedOnDialysateFlowML(), targetFillFlowRateLPM );
+            prevTargetFillVolumeML = getTargetFillVolumeBasedOnDialysateFlowML();
+            cmdStartDGFill( prevTargetFillVolumeML, targetFillFlowRateLPM );
         }
     }
     else
@@ -550,7 +554,8 @@
         // If the wait time has elapsed, trigger a fill command
         if ( timeWaitToFillMS <= 0 )
         {
-            cmdStartDGFill( getTargetFillVolumeBasedOnDialysateFlowML(), targetFillFlowRateLPM );
+            prevTargetFillVolumeML = getTargetFillVolumeBasedOnDialysateFlowML();
+            cmdStartDGFill( prevTargetFillVolumeML, targetFillFlowRateLPM );
         }
     }